Method and agent for the remediation of algal blooms

ABSTRACT

In one embodiment, a remediation agent and method of remediation of an algae bloom are disclosed. The remediation agent contains light absorbing compounds in a buoyant water semi-insoluble and biodegradable casein product. The remediation agent may be distributed by boat or seeded by airplane to remediate or prevent algae blooms.

CROSS REFERENCE TO RELATED APPLICATIONS

This non-provisional patent application incorporates by reference andclaims the benefit of U.S. Provisional Patent Application No. 61/433,510entitled “METHOD AND AGENT FOR THE REMEDIATION OF ALGAL BLOOMS” filed onJan. 17, 2011 by inventor John Peter Fuhrer.

FIELD

Aspects of the invention generally relate to a method and composition ofmatter for the lethal treatment of toxic algae blooms. Morespecifically, aspects of the invention relate to a method and acomposition of matter for destruction of toxic algae utilizing a lightabsorbing material that absorbs the critical wavelengths of lightrequired for the growth of toxic algae in a biodegradable productcapable of being distributed over a large target area.

BACKGROUND

Single-celled, microscopic algae naturally occur in the surface layer ofall aquatic environments. These plant-like organisms, known asmicroalgae or phytoplankton, form the base of the food web upon whichnearly all other marine organisms depend. An algae bloom occurs whenestuarine, marine, or fresh water algae accumulate rapidly and formdense patches that may be visible near the surface of water.

Certain species of phytoplankton contain photosynthetic pigments thatvary in color from green to brown to red. When algae are present in highconcentration, the water appears to be discolored or murky, varying incolor from white to almost black, often being red or brown. “Red Tide”is a common name for algae blooms, however, not all algae blooms aredense enough to cause water discoloration, and not all algae blooms arered.

Algae blooms typically involve the rapid growth of a single species ofphytoplankton in an area generally because of an increase in algaenutrients such as nitrogen and phosphorous. Only a small number of thethousands of species of marine phytoplankton are known to be harmful ortoxic. Red Tides are often caused by a species of phytoplankton known askarenia brevis. Algae blooms of karenia brevis may occur along coastalwaters. The density of these organisms during an algae bloom can exceedtens of millions of cells per liter of seawater, and often discolors thewater a deep reddish-brown hue.

Harmful Algae Blooms are associated with wildlife mortalities amongmarine and coastal species of fish, birds, marine mammals and otherorganisms. These mortalities are caused by exposure to various toxinsproduced by harmful phytoplankton.

The dinoflagellate Alexandrium fundyense, produces saxitoxin, theneurotoxin responsible for paralytic shellfish poisoning. Thedinoflagellate Karenia brevis, produces brevetoxin, the neurotoxinresponsible for neurotoxic shellfish poisoning. Brevetoxin, a potentneurotoxin, has been known to kill even large mammals such as bottlenosedolphins. California coastal waters also experience seasonal blooms ofPseudo-nitzschia, a diatom known to produce domoic acid, the neurotoxinresponsible for amnesic shellfish poisoning.

Phytoplankton toxins become concentrated in filter feeding marineorganisms when they consume large quantities of toxic plankton. Thesefilter feeders include shellfish, finfish, baleen whales, crustaceansand benthic invertebrates. Mussels, clams, oysters, and abalonescollected in areas affected by algae blooms can be dangerous for humanconsumption, leading to closure of shellfish beds for harvesting. Toxicalgae blooms cause millions of dollars of damage annually to sea foodproducing communities and to the farmed sea food industry.

Generally an increase of nutrients, such as nitrogen and phosphates, inan aquatic environment promotes the rapid growth of simple algae orplankton. The rapid growth of algae and plankton, however, isunsustainable. Oxygen depletion of the water column (hypoxia) can occurfrom excessive phytoplankton respiration. The eventual die-off of thealgae and their resulting degradation by bacteria may cause anoxia, acondition in which the decaying algae use up dissolved oxygen causingfish and other marine animals to suffocate.

Chemical treatment of algae blooms has been attempted using coppersulfate (bluestone) and chelated copper compounds as algaecides. Suchchemicals have their own restrictions and toxicity to marine animals.Besides being toxic, algaecides may indiscriminately kill offnon-blooming algae essential to the eco-system. Other treatments haveinvolved deploying powdered clay over a bloom to adsorb and sink thetoxic algae. Clay treatment, however, indiscriminately kills otherorganisms in the environment.

Biological treatment of an algae bloom may include introducing algaeeating species of fish such as grass carp or silver carp. However,introducing a non-native species of fish may be detrimental to the localeco-system and should be used with extreme caution.

Mechanically filtering an algae bloom may also be a viable treatment butrequires manpower and filtering equipment.

Thus what is needed are methods and agents for treating algae bloomsthat are more effective and environmentally friendly. The desired agentscould be deployed over sensitive eco-systems quickly and relativelyinexpensively.

BRIEF SUMMARY

Certain aspects of the invention are summarized by the claims.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an enlarged top view of an embodiment of the inventionillustrating a protein product containing light absorbing elements withair pockets suspended in the protein product.

FIG. 2 is a diagram illustrating various methods of deploying anembodiment of the invention.

FIG. 3 is a diagram illustrating embodiments of the invention containingdifferent light absorbing compounds.

FIG. 4A is an illustration of various embodiments of the invention beingused at different water depths.

FIG. 4B is a side view illustration of an embodiment of the inventiondispersed at different concentrations.

The figures are not drawn to scale so that elements, features, andsurface structure may be shown by example and are intended merely to beillustrative and non-limiting of the aspects of the invention that areclaimed.

DETAILED DESCRIPTION

This detailed description describes exemplary implementations that areillustrative of aspects of the invention, and so it is explanatory andnot limiting. The claims define inventive aspects. In the drawings, someelements have been omitted to more clearly show inventive aspects.

Introduction

Phytoplankton, are the autotrophic component of the plankton communityLike land plants, phytoplankton obtain energy through photosynthesis,and so usually live in the well-lit surface layer (termed the euphoticzone) of an ocean, sea, or lake. Phytoplankton absorb sun light atspecific wavelengths in order to conduct photosynthesis. Without lightat the required wavelengths, photosynthetic organisms die.

The surface of the water reflects some sunlight. The non-reflecteddescending light is absorbed by the water or particles of matter in thewater. At increasing depths of water, the intensity of the lightdecreases due to absorption. However, not all frequencies are absorbedequally. Red wavelengths of light are absorbed at the fastest rate withincreasing depth followed by orange, yellow, green, blue and indigowavelengths of light. Red frequencies or wavelengths of light do nottravel far below the surface of water before being absorbed. Frequenciesor wavelengths of light ranging in the blue and green spectrum penetratefurther into water.

Several classes of algae have evolved with different light absorbingpigments to take advantage of the different absorption depths of variouswavelengths of light. From the surface to depths of 6 meters (˜20 feet),where the proportion of red light is the highest, the dominant group maybe green algae, which have the same photosynthetic pigments as landplants.

Between 6 m to 30 m (˜20 ft to 100 ft), where yellow light abounds,brown algae may dominate. At depths below 35 m (˜116 ft), red algae areabundant because of the abundance of green light. These algae havephycoerithrin, a red pigment that makes the absorption of green lightpossible.

There are species of algae that are the exception to these rules.Cladophora, one of the most common green algae, can grow at depths of 80m (˜266 ft). Furthermore, some algae change pigments depending on thelight they are exposed to. Oscillatoria, a photosynthetic blue-greenalgae, turns green-bluish in red light, because it produces the bluepigment phycocyanin. However, when exposed to green or blue light, itturns red because it can synthesize the red pigment phycoerithrin.

Remediation Agent

A remediation agent and methods for algae bloom remediation using saidagent are disclosed. Specifically, a method and agent for treating algaeblooms is disclosed using a buoyant biodegradable protein wafercontaining proteins engineered to absorb light at wavelengths utilizedby algae. The biodegradable thin wafer or flake can be distributed fromboats or seeded from aircraft for the remediation of harmful algalblooms.

Referring now to FIG. 1, an embodiment of a remediation agent 100 isillustrated. The remediation agent 100, a composition of matter,includes a product 110, light absorbing compound 120, and one or moreair pockets or bubbles 130. The light absorbing compound 120 may beadapted to block a range of frequencies or wavelengths of light used byalgae for photosynthesis. The remediation agent 100 may be deployed at atarget site where an algae bloom has occurred, is occurring, or islikely to occur.

The product 110 is preferably biodegradable, non-toxic, watersemi-insoluble and easily manufactured. The air pockets or bubbles 130may be suspended in the product 110 to aid in buoyancy of theremediation agent 100 and float it over algae located near the surfaceof water. Alternatively, an inert material (e.g., sand, silt, mud,sediment etc.) with a specific gravity greater than water may be used tosink the remediation agent to algae located at various depths below thesurface of the water.

In one embodiment of the invention, the product 110 is a casein product.Casein is a water soluble biodegradable protein found in mammalian milk.When in milk, casein occurs as a suspension of particles calledmicelles. A typical micelle in aqueous solution forms an aggregate withthe hydrophilic “head” regions in contact with surrounding solvent,sequestering the hydrophobic single tail regions in the micelle center.

Casein may be isolated from milk by several methods. Casein can beprecipitated from milk by an enzymatic method or by a mild acidtreatment method, for example.

It may be desirable to make the proteins that comprise this productsemi-insoluble in water so that the product will slowly dissolve inwater over a predetermined period of time. The protein product isultimately digested by natural environmental organisms.

Various methods may be used to produce semi-insoluble protein materialthat can be formed into shapes and can be made to contain many types ofcomponents. One such method for casein protein is described in U.S. Pat.No. 6,379,726 issued to Peggy Tomasula on Apr. 30, 2002 and U.S. PatentApplication Pub. No. 2004/0018294 filed by Peggy Tomasula on Feb. 10,1999, both of which are incorporated herein by reference. Alternatively,other methods may be used to link or cross-link proteins, such as by achemical approach, an aging approach, or some other molecule alignmentprocess so the protein molecules are aligned or aggregated so as toresist being fully soluble in water and thus allow a predeterminedperiod of time for the product to function as a remediation agent beforedissolving into water and/or biodegrading.

The casein product 110 may be formed into any shape. In one embodimentof the invention the casein product 110 may take the shape of a disc.The discs may be a small, substantially flat, thin circular shape.Although the casein product 110 is described and illustrated as a disc,the scope of the invention covers other shapes.

Casein is biodegradable and non-toxic. In a semi-insoluble form, thecasein product 110 will eventually degrade or dissolve in water. Caseinproduct 110 deployed at an algae bloom site will eventually biodegradewithout the need for labor intensive cleaning. Unlike algaecides whichmay be toxic to marine life, casein is an edible milk protein and thusless likely to harm marine life that may contact or eat the casein.

While the product 110 has been described as being formed of caseinprotein, the product may be formed of other proteins, such as soyprotein, that may be made semi-insoluble and absorb or suspend the lightabsorbing compounds. Methods may be used to link or cross-link proteins,such as by a chemical approach, an aging approach, or some othermolecule alignment process so the protein molecules are aligned toresist being readily soluble in water and allow a predetermined periodof time for the light absorbing compound 120 to inhibit algaephotosynthesis before dissolving into water and/or biodegrading.

Light absorbing compound 120 may be created by chemically attachingprosthetic organic molecules to protein backbones. These organicmolecules are referred to as “prosthetic organic molecules” because theyare not native or natural components of the protein backbones, but areadded chemically after the proteins are synthesized. Such prostheticorganic molecules are chemically synthesized and attached to the proteinbackbones by standard chemical reactions common in the field ofchemistry. Light absorbing compound 120 may be chemically analogous tothe antennae structures in natural proteins such as the phycobilins inphotosynthestic algae or the light absorbing antennae in syntheticfluorescent proteins. Light absorbing compound 120 is preferablybiodegradable and engineered to absorb light at the critical wavelengthsused by algae.

The prosthetic organic molecules contained in light absorbing compound120 may be chromophores, a.k.a. pigments, molecules that absorb certainwavelengths of light and reflect other wavelengths of light. An exampleof a prosthetic organic molecule is carotenoid pigment which absorbsblue and green light. Another is the phycocyanin pigment which absorbsorange and red light. The prosthetic organic molecule may be engineeredto absorb substantially the same wavelength of light as algae beingremediated. For example, cyanobacteria or blue green algae useschlorophyll a to absorbs and process light in photosynthesis.Chlorophyll a absorbs energy from the violet-blue and reddish orange-redwavelengths. To remediate a bloom of cyanobacteria, wavelengths between430 nm and 650 nm would need to be absorbed by the light absorbingcompound 120. Thus, to remediate cyanobacteria, chromophores such ascarotenoid and phycocyanin pigments may be attached to a proteinbackbone to make light absorbing compound 120. Light absorbing compound120 would be added to product 110 with one or more optional air pockets130 to create remediation agent 100. Remediation agent 100 may bedispersed over the cyanobacteria bloom to inhibit photosynthesis andeventually destroy the algae bloom.

Although, the embodiment of the invention described above preferablycontains a biodegradable prosthetic organic molecule used as achromophore, other light absorbing materials such as metal complexchromophores or nonorganic compositions may be used. Similarly, althoughair pockets 130 are shown allowing the remediation agent 100 to float atthe surface of the water, its buoyancy may be varied to float atdifferent depths. Air pocket 130 may also be filled with differentgasses such as nitrogen, helium, hydrogen, oxygen, methane, and ammonia.

Methods of Delivery

The invention may be deployed to remediate an algae bloom by aerialdispersal, shipboard dispersal, or even by hand. Use of aerial dispersalmay be preferred in remote areas where ships may take days or weeks torespond to an algae bloom. However, the use of ships may be preferredwhere large quantities of the remediation agent 100 may be used.

Referring now to FIG. 2, a diagram illustrates various methods ofdeploying remediation agent 100. In one method of deployment, anaircraft 210 (e.g. airplane, helicopter, or balloon) is shown droppingremediation agent 100 onto algae bloom 220 at the surface of the ocean230. In another method, a ship 240 is shown dispersing remediation agent100 by propelling the remediation agent 100 onto the algae bloom 220.Although the remediation agent 100 is shown being propelled over theside of the ship 240, a simpler method of dropping the remediation agent100 overboard may be used, such as by a spreading mechanism or by hand,to achieve similar results. One or more of these and other methods ofdeploying the remediation agent 100 may be used together or individuallyon algae blooms.

In FIG. 2, a sensitive eco-system 250 is endangered by the encroachingalgae bloom 220. Aircraft 210 may drop remediation agent 100 directly onthe algae bloom 220 and/or onto the sensitive eco-system 250.Alternatively, remediation agent 100 may be manually applied onto algaeblooms adjacent to land by such methods as by hand, wheeled spreaders(e.g., a fertilizer spreader), dump trucks or spreading trucks.Remediation agent 100 is more environmentally friendly than algaecidesand will biodegrade, thus deploying remediation agent 100 directly ontothe sensitive eco-system 250 is a viable option.

Methods of deployment may require consideration of several factors, suchas type of algae, location of the algae bloom, and amount of areacovered by the algae bloom. For example, larger algae blooms closer toshore may be more efficiently treated using shipboard deployment of theremediation agent 100.

Aerial dispersal over wide areas may be accomplished with equipmentsimilar to that used for dispersing flame retardants or fertilizer. Alow flying fixed wing aircraft 210 or helicopter may be used toaccurately target dispersal areas. Aircraft 210 may be capable ofdeploying the remediation agent 100 to remote areas not readilyaccessible to vehicles or by foot. Furthermore, aircraft may be capableof reaching a target site faster than other dispersal methods, possiblypreventing or mitigating harm to sensitive eco-system 250.

Targeting Different Algae Types

Although red tides are infamous, they are but one of the many types ofharmful algae blooms (HABs). Some algae blooms are harmful at lowconcentrations because the algae involved produces dangerousneurotoxins. Other HABs such as macroalgae may not seem harmful, butreduces the biodiversity of a habitat. For example, the macroalgaeCaulerpa spp. (seaweed) may dominate a coral reef, reducing not only theplant life on the coral reef but also the marine life that depends onthe biodiversity of coral reefs.

Algae have evolved to take advantage of different frequencies of lightthat filter through the aquatic depths. Different types of algae maythrive at different depths. Green algae may dominate at the upper layerjust below the surface. Brown and golden algae occupy the middle layersand red algae the bottom layer. There are exceptions to these rules, butin general different algae types exist at different depths.

Referring now to FIG. 3, alternate embodiments of the invention areillustrated to address different types of algae. The embodimentsdepicted in FIG. 3, differ by the type of light absorbing compound 120(not shown in FIG. 3, see FIG. 1) each contains. Light absorbingcompound 120 filters light out from reaching algae bloom 320A. The lightabsorbing compound 120 may be selected to absorb light in a range ofwavelengths narrower than the range of wavelengths corresponding to thevisible spectrum. For example, remediation agent 300A may contain alight absorbing compound 120 that predominantly absorbs lightfrequencies in the red and yellow ranges, shown as light 310A. Light311A of a different wavelength is allowed to pass through remediationagent 300A. Remediation agent 300B may contain a different lightabsorbing compound 120 that absorbs the entire spectrum of visible lightor at least a large portion of the visible spectrum to filter light out.Remediation agent 300C may be adapted to absorb light frequencies in theblue and green range. Light 311C of other wavelengths may pass throughremediation agent 300C.

Different types of light absorbing compound 120 may be mixed together inremediation agent 100. For example, a light absorbing compound 120absorbing primarily red light may be mixed with a light absorbingcompound 120 absorbing primarily blue light. Such an embodiment ofremediation agent 100 may be advantageous in combating algae bloomswhere the algae can change photosynthetic pigments. Alternatively,instead of light absorbing compound, a biodegradable chemical compoundwith light absorbing properties may be added to protein product 110.

It may be advantageous to have remediation agent 100 absorb differentwavelengths of light. Algae are naturally occurring phytoplankton.Indiscriminately killing off all algae in an area may be harmful to theenvironment. Adapting the remediation agent 100 to absorb a narrowerrange of light wavelengths, allows the algae bloom to be targeted withless impact on other types of algae or other plant life.

Referring now to FIG. 4A, a method and agent of targeting algae bloomsat different depths is illustrated. In order to combat submerged algae420A-420B, an inert material 140 (e.g. sand, silt, dirt, etc.) (seeFIG. 1) with a specific gravity greater than water (e.g., specificgravity of fresh water in the case of fresh water algae bloom orspecific gravity of salt water in the case of a salt water algae bloom)may be used to sink the remediation agents 400A-400B towards algaeblooms below the surface of the water 230. The closer the remediationagent, the more light may be filtered away from the algae bloom.

Remediation agent 400A and 400B are alternative embodiments ofremediation agent 100 that sink to different depths of water. Thebuoyancy of remediation agent 400A may be altered so that theremediation agent 400A is slightly denser than surface temperaturewater. Generally, water is colder the deeper it gets. Colder water isdenser than warm water. Thus at some level, the remediation agent 400Awill stop sinking. Remediation agent 400B may be made relatively heavierthan remediation agent 400A to sink to an even lower depth. Thesealternative embodiments may be created by adding to the remediationagent 100, an inert material 140 with a specific gravity greater thanwater. Alternative embodiments of the remediation agent 400A and 400Bmay or may not include air pockets 130 in their makeup to achieve adesired buoyancy and depth below the water surface.

The amount of remediation agent 100 to be deployed depends on severalfactors. Sufficient remediation agent 100 should be dispersed tosubstantially cover the algae bloom to block out selected ranges ofwavelengths of light. The concentration or packing density of the flakesor particles of remediation agent 100 comprising the covering layer ofremediation agent 100 may determine how much photosynthesis is inhibitedand amounts of algae that are killed off. Generally the thicker or moreconcentrated the covering layer of remediation agent 100, a largeramount of light will be absorbed. The thickness of the covering layermay be affected by the thickness of the individual flakes, with thickerflakes generally forming thicker covering layers and absorbing morelight. More light absorption generally inhibits more photosynthesis,thereby destroying larger amounts of algae.

Referring now to FIG. 4B, embodiments of the invention may be deployedat different concentrations upon the surface or at differentconcentrations below the surface of water. FIG. 4B illustratesremediation agents 400C and 400D shown being deployed at a firstconcentration upon the surface of the water. Remediation agents 400Ethrough 400G are shown being deployed at a second concentration upon thesurface of the water that is greater than the first concentration asthere is less space between the particles. The concentration or packingdensity is initially affected by how many particles are deployed in agiven area of an algae bloom. The more desirable concentration wouldeffectively achieve a light absorbing sheet on the surface or below thesurface of the water. Subsequent natural effects (e.g., waves, currents,wind,) and man made effects (e.g., boat wake, propeller wash, or machinestirring or dispersing) may disperse remediation agent 100 and reduceits density at the surface of water or at depths in the water.

CONCLUSION

While this specification includes many specifics, these should not beconstrued as limitations on the scope of the disclosure or of what maybe claimed, but rather as descriptions of features specific toparticular implementations of the disclosure. Certain features that aredescribed in this specification in the context of separateimplementations may also be implemented in combination in a singleimplementation. Conversely, various features that are described in thecontext of a single implementation may also be implemented in multipleimplementations, separately or in sub-combination. Moreover, althoughfeatures may be described above as acting in certain combinations andeven initially claimed as such, one or more features from a claimedcombination may in some cases be excised from the combination, and theclaimed combination may be directed to a sub-combination or variationsof a sub-combination. Accordingly, the claimed invention is limited onlyby the claims that follow below.

1. A remediation agent for treating algae blooms, comprising: a product;and light absorbing compounds suspended in the product, the lightabsorbing compounds to absorb light and inhibit photosynthesis in analgae bloom.
 2. The remediation agent of claim 1, wherein the lightabsorbing compounds are organic molecules attached to protein backbones.3. The remediation agent of claim 1, wherein the product is a protein.4. The remediation agent of claim 1, wherein the light absorbingcompounds are biodegradable light absorbing proteins.
 5. The remediationagent of claim 3, wherein the protein is casein.
 6. The remediationagent of claim 1, further comprising: a plurality of pockets of gassuspended in the product adapted to buoy the remediation agent towards asurface of water.
 7. The remediation agent of claim 6, wherein the gasis one or more of air, nitrogen, helium, hydrogen, oxygen, methane, andammonia.
 8. The remediation agent of claim 1, further comprising: inertmaterial with a specific gravity greater than water suspended within theproduct to adjust the buoyancy of the remediation agent down away from asurface of water.
 9. (canceled)
 10. The remediation agent of claim 1,wherein the light absorbing compound absorbs light in a range ofwavelengths corresponding to a range of wavelengths useable by algae.11. A method of remediation of an algae bloom, the method comprising:examining an algae bloom to determine borders of an area of the algaebloom; selecting a first deployment means for a remediation agent, theremediation agent including a light absorbing compound suspended in abiodegradable protein product to inhibit photosynthesis in the algae;and with the first selected deployment means, deploying the remediationagent over the area of the algae bloom to cover the algae bloom.
 12. Themethod of claim 11, wherein the protein product is casein.
 13. Themethod of claim 11, further comprising: suspending a light absorbingcompound in the biodegradable protein product to absorb a predeterminedrange of wavelengths of light.
 14. The method of claim 11, furthercomprising: suspending a gas in pockets within the protein product toadjust the buoyancy of the remediation agent towards a surface of water.15. The method of claim 14, wherein the gas is one or more of air,nitrogen, helium, hydrogen, oxygen, methane, and ammonia.
 16. The methodof claim 11, further comprising: suspending an inert material with aspecific gravity greater than water within the protein product to adjustthe buoyancy of the remediation agent down away from a surface of water.17. The method of claim 13, wherein the protein product is casein. 18.The method of claim 11, wherein the deployment means is one or more of aspreader, a truck, a ship, and an airplane.
 19. (canceled) 20.(canceled)
 21. A method of remediation of an algae bloom, the methodcomprising: receiving light into a biodegradable protein product inwater; absorbing light in a predetermined range of wavelengths with alight absorbing compound in the product to inhibit algae in an algaebloom; and dissolving the biodegradable protein product into the waterafter a predetermined period of time.
 22. The method of claim 21,further comprising: biodegrading the biodegradable protein product inthe water.
 23. The method of claim 21, further comprising: passing lightof wavelengths outside the range of wavelengths;